Sealing device

ABSTRACT

A sealing device which can stably exhibit a sealing function and enables a reduction in the number of components as well as in a radial size of the device. The sealing device includes a metal cartridge case (110) having a case main body (111) and a first supporting portion (113), a resin sealing member (120), an elastic sealing member (130), and a metal fixing member (140). An outer diameter of a cylindrical portion (141) of the fixing member (140) is set to be equal to or smaller than an inner diameter of the case main body (111), and the cylindrical portion (141) and the case main body (111) are secured by welding. The resin sealing member (120) and the elastic sealing member (130) are fixed by being held in between the first supporting portion (113) and a second supporting portion (142) of the fixing member (140).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/2015/068299, filed Jun. 25, 2015 (now WO 2016/009803A1), whichclaims priority to Japanese Application No. 2014-146540, filed Jul. 17,2014. The entire disclosures of each of the above applications areincorporated herein by reference.

FIELD

The present disclosure relates to a sealing device that seals an annulargap between a housing and a shaft.

BACKGROUND

Sealing devices are used in car water pumps for preventing water leakage(see Patent Literature 1). A sealing device according to a conventionalexample will be described with reference to FIG. 7. FIG. 7 is aschematic cross-sectional view of the sealing device according to theconventional example. The illustrated sealing device 700 serves thefunction of sealing an annular gap between a shaft hole provided in ahousing (not shown) and a rotating shaft (not shown) inserted throughthis shaft hole.

In the sealing device 700 according to this conventional example, aresin sealing member 720 and an elastic sealing member 730 made ofrubber or the like are fixed to a cartridge case 710 so that they can behandled as one component. The cartridge case 710 includes a cylindricalcase main body 711 fitted to an inner circumferential surface of theshaft hole, an outward flange 712 extending radially outward from oneend portion of the case main body 711 on a sealed fluid side, and aninward flange 713 extending radially inward from an end portion of thecase main body 711 opposite from the sealed fluid side. The resinsealing member 720 is firmly secured by being held in between a pair offirst and second metal supporting members 740 and 750 that are fixedlyfitted to each other. The elastic sealing member 730 includes an outerperipheral sealing portion 731 that seals an annular gap between theouter circumferential surface of the second supporting member 750 andthe inner circumferential surface of the case main body 711, and asealing lip portion 732 slidable on the outer circumferential surface ofthe rotating shaft.

With the resin sealing member 720 fixed by the first supporting member740 and second supporting member 750, and the elastic sealing member 730being mounted on the inner circumferential side of the case main body711, an adapter 760 is press-fitted. Accordingly, the resin sealingmember 720 and elastic sealing member 730 are fixedly set in position inthe axial direction. The distal end of the inward flange 713 ispress-joined so that the resin sealing member 720 and elastic sealingmember 730 are fixedly set in position in the radial direction (seepress-joined portion 714 in the drawing).

The adapter 760 is press-fitted, as mentioned above. Generally, it isdifficult to achieve precise positioning of press-fitted members becauseof the high sliding resistance during the press-fitting. In the casewith the sealing device 700 according to the conventional example shownin FIG. 7, however, the resin sealing member 720 is firmly secured bythe first supporting member 740 and second supporting member 750, andthe outer circumferential side of the second supporting member 750 iselastically pressed by the outer peripheral sealing portion 731 of theelastic sealing member 730. The resin sealing member 720 is thereforemaintained in a stable attitude. Accordingly, the resin sealing member720 fully exhibits its function. The sealing function on the outercircumferential side is also fully exhibited, since the annular gapbetween the outer circumferential surface of the second supportingmember 750 and the inner circumferential surface of the case main body711 is sealed by the outer peripheral sealing portion 731 of the elasticsealing member 730.

As described, the illustrated sealing device 700 fully exhibits itsfunction as a sealing device even if the positioning precision of theadapter 760 is low. The shortcoming of this sealing device 700, however,is that the number of parts is large as it requires several components.Generally, with an increase in the number of parts, not only the costincreases, but also measurement errors tend to be large, so thatstricter dimension control is necessary. Another shortcoming is that itis difficult to reduce the radial size because of the configuration inwhich the annular gap between the outer circumferential surface of thesecond supporting member 750 and the inner circumferential surface ofthe case main body 711 is sealed by the outer peripheral sealing portion731 of the elastic sealing member 730. It may therefore be impracticalto adopt the configuration of the above-described sealing device 700 ifthe annular gap between the housing and the shaft is small.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Patent No. 5037682

SUMMARY Technical Problem

An object of the present disclosure is to provide a sealing device thatcan stably exhibit the sealing function and enables a reduction in thenumber of components as well as in the radial size.

Solution to Problem

The present disclosure adopts the following means to achieve the objectnoted above.

Specifically, a sealing device of the present disclosure is a sealingdevice for sealing an annular gap between a shaft hole provided in ahousing and a shaft inserted through the shaft hole, the sealing devicecomprising: a metal cartridge case including a cylindrical case mainbody fitted to an inner circumferential surface of the shaft hole, and afirst supporting portion extending radially inward from an end portionof the case main body on an opposite side to a sealed fluid side; aresin sealing member provided adjacent to the first supporting portionon the sealed fluid side and having a sealing portion that is slidableon an outer circumferential surface of the shaft; an elastic memberprovided adjacent to the resin sealing member on the sealed fluid side;and a metal fixing member including a cylindrical portion fixed to aninner circumferential surface of the case main body, and a secondsupporting portion extending radially inward from an end portion of thecylindrical portion on the opposite side to the sealed fluid side,wherein an outer diameter of the cylindrical portion is set to be equalto or smaller than an inner diameter of the case main body, and thecylindrical portion and the case main body are being secured by welding,and the resin sealing member and the elastic member are fixed by beingheld in between the first supporting portion and the second supportingportion.

In the present disclosure, an outer diameter of the cylindrical portionin the metal fixing member is set to be equal to or smaller than theinner diameter of the case main body, and a configuration is adopted inwhich the cylindrical portion and case main body are secured by welding.Accordingly, in comparison to the case where the fixing member issecured by press-fitting, the fixing member can be positioned moreprecisely. Therefore, a separate component dedicated for fixing theresin sealing member in position as was conventionally practiced (suchas the first supporting member 740 and second supporting member 750 madeof metal in the conventional example described above) is not required.Accordingly, the number of components can be reduced. Moreover, sincethe fixing member can be positioned more precisely, the attitude of theresin sealing member can be made stable. Thus the sealing function canbe exhibited in a stable manner. Also, there is no need to dispose partof an elastic component (such as the outer peripheral sealing portion731 of the elastic sealing member 730 in the conventional exampledescribed above) on the outer side of the outer circumferential surfaceof the resin sealing member, so that the sealing device can be reducedin the radial size.

Preferably, an annular space may be formed between an outer wall surfaceof a portion connecting the cylindrical portion and the secondsupporting portion of the fixing member, and the elastic member.

Accordingly, the heat generated during the welding is prevented frombeing conducted to the elastic member.

Preferably, the elastic member may include: an annular body portionprovided between the resin sealing member and the second supportingportion and having an outer circumferential surface that is in closecontact with the inner circumferential surface of the case main body;and a sealing lip portion provided integrally with the body portion andbeing slidable on the outer circumferential surface of the shaft.

Accordingly, the elastic member can provide a sealing between the innercircumferential surface of the case main body and the outercircumferential surface of the shaft. Also, as described above, sincethe positioning precision of the fixing member can be improved, theelastic member can be positioned more precisely, so that the attitude ofthe elastic member is made stable. Also, the body portion of the elasticmember can make close contact with the inner circumferential surface ofthe case main body more precisely. Accordingly, the sealing function onthe outer circumferential side is fully achieved without the need todispose part of an elastic component (such as the outer peripheralsealing portion 731 of the elastic sealing member 730 in theconventional example described above) on the outer side of the outercircumferential surface of the resin sealing member.

Preferably, the fixing member may be fixed to the case main body at aposition where a repulsive force from the elastic member applied on thesecond supporting portion is within a predetermined range.

Accordingly, the resin sealing member and elastic member can be fixed inposition precisely.

Various configurations described above may be adopted in as manycombinations as possible.

Advantageous Effects of the Disclosure

As described above, according to the present disclosure, the sealingdevice can stably exhibit the sealing function and enables a reductionin the number of components as well as in the radial size.

DRAWINGS

FIG. 1 is a schematic cross-sectional view of a water pump.

FIG. 2 is a schematic cross-sectional view of a sealing device accordingto Example 1 of the present disclosure.

FIG. 3 is a diagram for explaining how the sealing device according toExample 1 of the present disclosure is assembled.

FIG. 4 is a schematic cross-sectional view of a sealing device accordingto Example 2 of the present disclosure.

FIG. 5 is a schematic cross-sectional view of a sealing device accordingto Example 3 of the present disclosure.

FIG. 6 is a schematic cross-sectional view of a sealing device accordingto Example 4 of the present disclosure.

FIG. 7 is a schematic cross-sectional view of a sealing device accordingto a conventional example.

DETAILED DESCRIPTION

Hereinafter, modes for implementing the present disclosure will beexemplarily described in detail based on examples thereof with referenceto the drawings. However, the dimensions, materials, shapes, relativearrangements and so on of constituent parts described in the examplesare not intended to limit the scope of the present disclosure to thesealone in particular unless specifically described.

APPLICATION EXAMPLES

Application examples of the sealing device 100 according to an exampleof the present disclosure will be described with reference to FIG. 1.FIG. 1 is a schematic cross-sectional view of a car water pump 10. Thewater pump 10 includes a rotating shaft 21 and a housing 30 with a shafthole for the rotating shaft 21 to pass through. A bearing 22 is attachedto the rotating shaft 21 for smooth rotation of the rotating shaft 21. Apulley 23 is attached to one end side of the rotating shaft 21, to whicha rotary drive force is imparted via a belt or the like (not shown),while an impeller 24 is attached to another end side to pump coolingwater (LLC) under pressure. The sealing device 100 according to thepresent example is disposed in an annular gap between the rotating shaft21 and the housing 30 in order to prevent this cooling water fromleaking to the outside (i.e., the opposite side (A) to the sealed fluidside (L)). Namely, in the present example, the sealed fluid is coolingwater. Note that the sealing device according to the present disclosuremay be applied to other purposes.

Example 1

The sealing device 100 according to Example 1 of the present disclosurewill be described with reference to FIG. 2 and FIG. 3. The sealingdevice 100 according to the present example serves the function ofsealing an annular gap between a shaft hole provided in a housing 300and a shaft 200 inserted through this shaft hole. When the sealingdevice 100 is applied to the car water pump 10 described above, thehousing 300 corresponds to the above-mentioned housing 30, and the shaft200 corresponds to the above-mentioned rotating shaft 21.

<Configuration of Sealing Device>

The sealing device 100 according to the present example will bedescribed with reference particularly to FIG. 2. The sealing device 100is configured such that a resin sealing member 120 and an elasticsealing member 130, which is an elastic member (made of an elasticmaterial such as rubber), are fixed to a cartridge case 110 so that theycan be handled as one component. This sealing device 100 is made up ofthese three parts, a metal fixing member 140 for fixing the resinsealing member 120 and the elastic sealing member 130 to the cartridgecase 110, and an outer peripheral sealing member 150 provided on theouter circumference of the cartridge case 110.

The cartridge case 110 includes a cylindrical case main body 111, anoutward flange 112 provided on the sealed fluid side (L) of the casemain body 111, and a first supporting portion 113 provided on theopposite side (A) to the sealed fluid side (L) of the case main body111, these being in one piece.

The case main body 111 is fixed to the inner circumferential surface ofthe shaft hole formed in the housing 300 by being fitted therewith. Theouter peripheral sealing member 150, which is an elastic coating, isprovided on the outer circumference of this case main body 111. Theouter peripheral sealing member 150 ensures prevention of water leakagethrough between the sealing device 100 and the shaft hole in the housing300. In the process of fixedly fitting the case main body 111 to theshaft hole formed in the housing 300, part of the outer peripheralsealing member 150 is scraped off. However, there is an annular space S1formed by a chamfer 310 near the open edge of the shaft hole in thehousing 300. Therefore, shavings of the outer peripheral sealing member150 being scraped off are accumulated in this annular space S1.Accordingly, the possibility of shavings entering into the sealed fluid(L) is reduced.

The outward flange 112 is formed to extend radially outward from one endportion of the case main body 111 on the sealed fluid side (L). Thecartridge case 110 is fitted to the shaft hole in the housing 300 untilthis outward flange 112 abuts on an end face of the housing 300, wherebythe cartridge case 110 is set in position.

The first supporting portion 113 is formed to extend radially inwardfrom one end portion of the case main body 111 on the opposite side (A)to the sealed fluid side (L). A distal end portion of this firstsupporting portion 113 is formed to incline toward the direction of thesealed fluid (L) so as to form a back-up portion 114 that supports theresin sealing member 120. The first supporting portion 113 furtherincludes a plurality of circumferentially spaced protrusions 113 a.These protrusions 113 a are formed so as to bite into the resin sealingmember 120. Accordingly, the possibility of the resin sealing member 120coming off of the cartridge case 110 is reduced.

The resin sealing member 120 includes a body portion 121, and a sealingportion 122 extending from a radially inner side of the body portion 121toward the direction of the sealed fluid (L), these being in one piece.The resin sealing member 120 is provided adjacent to the firstsupporting portion 113 on the sealed fluid side (L). The body portion121 makes close contact with the first supporting portion 113, while theinner circumferential surface of the sealing portion 122 makes closecontact with the outer circumferential surface of the shaft 200 so as tobe slidable thereon. A portion between the body portion 121 and thesealing portion 122 that is bent in a curve is supported by the back-upportion 114. The resin sealing member 120 is a disc-like member with ahole in the center before being assembled to the cartridge case 110(when not subjected to external forces). Having said that, the innercircumferential end portion of the resin sealing member 120, which willbe the sealing portion 122, should preferably be bent in advance to someextent toward the direction of the sealed fluid (L) in order tofacilitate insertion of the shaft 200.

The elastic sealing member 130 includes an annular body portion 131, acylindrical portion 132 extending from a radially inner side of the bodyportion 131 toward the direction of the sealed fluid (L), and a sealinglip portion 133 inclined radially inward from the end portion of thecylindrical portion 132, these being in one piece. The elastic sealingmember 130 is provided adjacent to the resin sealing member 120 on thesealed fluid side (L). The body portion 131 makes close contact with thebody portion 121 of the resin sealing member 120 on the sealed fluidside (L), while the inner circumferential surface of the cylindricalportion 132 at least partially makes close contact with the outercircumferential surface of the sealing portion 122 of the resin sealingmember 120. The sealing lip portion 133 makes close contact with theouter circumferential surface of the shaft 200 so as to be slidablethereon at a point further closer to the sealed fluid (L) than thedistal end of the sealing portion 122 of the resin sealing member 120.The body portion 131 is provided between the body portion 121 of theresin sealing member 120 and a second supporting portion 142 of thefixing member 140 to be described later, and formed such that its outercircumferential surface makes close contact with the innercircumferential surface of the case main body 111.

The metal fixing member 140 is made up of a cylindrical portion 141, thesecond supporting portion 142 extending radially inward from an endportion on the opposite side (A) to the sealed fluid side (L) of thecylindrical portion 141, and a tapered portion 143 extending from thedistal end of the second supporting portion 142 toward the direction ofthe sealed fluid (L) so as to increase in diameter. The cylindricalportion 141 is fixed to the inner circumferential surface of the casemain body 111. The outer diameter of the cylindrical portion 141 is setto be equal to or smaller than the inner diameter of the case main body111, and the cylindrical portion 141 and the case main body 111 aresecured by welding. The cylindrical portion 141 may be welded at an endportion on the sealed fluid side (L) as indicated by arrow X1 in FIG. 2,or at an interface between the inner circumferential surface of the casemain body 111 and the outer circumferential surface of the cylindricalportion 141 as indicated by arrow X2 in FIG. 2. In the case with thelatter, however, the welding point should preferably be near the endportion of the cylindrical portion 141 on the sealed fluid side (L) sothat the heat generated during the welding is conducted less to theelastic sealing member 130. The portion bent in a curve that connectsthe second supporting portion 142 and the tapered portion 143 provides asupport for the outer circumferential surface of the cylindrical portion132 of the elastic sealing member 130. Accordingly, the sealing lipportion 133 is prevented from separating from the outer circumferentialsurface of the shaft 200. The tip of the tapered portion 143 isseparated from the outer circumferential surface of the cylindricalportion 132 of the elastic sealing member 130 so that it is unlikely todamage the cylindrical portion 132.

The resin sealing member 120 and the elastic sealing member 130 arefixed by being held in between the first supporting portion 113 of thecartridge case 110 and the second supporting portion 142 of the fixingmember 140. An annular space S2 is formed between an outer wall surfaceof the portion 144 connecting the cylindrical portion 141 and the secondsupporting portion 142 of the fixing member 140, and the elastic sealingmember 130.

<Assembling Procedure of the Sealing Device>

An assembling procedure of the sealing device 100 according to thepresent example will be described with reference particularly to FIG. 3.In the present example, when assembling the sealing device 100, areceiving jig 500 that provides a base, a pressing member 600, and alaser light source 650 are used. The receiving jig 500 includes a baseportion 510 and a cylindrical portion 520. First, the cartridge case110, to which the resin sealing member 120, elastic sealing member 130,and fixing member 140 have already been mounted, is assembled to thisreceiving jig 500. Since the outer diameter of the cylindrical portion141 of the fixing member 140 is set to be equal to or smaller than theinner diameter of the case main body 111, the fixing member 140 can bemounted to the cartridge case 110 with hardly any pressure. Thecylindrical portion 520 of the receiving jig 500 has an inner diameterslightly larger than the outer diameter of the case main body 111.Therefore, hardly any pressure is required when fitting the cartridgecase 110 into the receiving jig 500.

Next, the second supporting portion 142 of the fixing member 140 ispressed toward the base portion 510 of the receiving jig 500 by the tipof a cylindrical pressing portion 610 provided on the pressing member600. With the pressing member 600 kept in position where a pressurewithin a predetermined range is being loaded, a laser beam L is emittedfrom the laser light source 650 to weld the cylindrical portion 141 andthe case main body 111 securely together. As mentioned above, since theouter diameter of the cylindrical portion 141 of the fixing member 140is set to be equal to or smaller than the inner diameter of the casemain body 111, there is hardly any friction between the cylindricalportion 141 and the case main body 111. Accordingly, the pressureapplied by the pressing member 600 on the second supporting portion 142of the fixing member 140 is equal to the repulsive force from theelastic sealing member 130 applied on the second supporting portion 142.Thus, through the welding described above, the fixing member 140 isfixed to the case main body 111 at a position where the repulsive forcefrom the elastic sealing member 130 applied on the second supportingportion 142 is within a predetermined range.

Preferably, a load sensor may be provided to one of the receiving jig500 and the pressing member 600, so that the movement of the pressingmember 600 is stopped when the load detected by this load sensor fallswithin a predetermined range, to carry out the welding. With the laserlight source 650 alone being fixed, the sealing device 100 may berotated together with the receiving jig 500 and the pressing member 600while the laser beam L is emitted, so that the sealing device can bewelded all around. While the welding is performed with a laser beam L inthe present example, various other known techniques (such as TIGwelding) may be adopted for the welding. The welding may be performedall around as described above, or at several circumferentially spacedpoints.

<Advantages of the Sealing Device According to the Present Example>

As described above, in the sealing device 100 according to the presentexample, the outer diameter of the cylindrical portion 141 of the metalfixing member 140 is set to be equal to or smaller than the innerdiameter of the case main body 111. In addition, a configuration isadopted in which the cylindrical portion 141 and the case main body 111are secured by welding. Accordingly, in comparison to the case where thefixing member 140 is press-fitted, the positioning precision of thefixing member 140 can be improved. Therefore, a separate componentdedicated for fixing the resin sealing member 120 in position as wasconventionally practiced (such as the first supporting member 740 andsecond supporting member 750 made of metal in the conventional exampledescribed above) is not required. Accordingly, the number of componentscan be reduced. Since the fixing member 140 has the cylindrical portion141, and this cylindrical portion 141 is secured to the case main body111, the fixing member 140 is prevented from tilting in the axialdirection relative to the case main body 111. Thus, the attitude of thefixing member 140 can be maintained stably. Assuming that the fixingmember 140 has no cylindrical portion 141, the second supporting portion142 could be fixedly welded to the case main body 111 at the outerperipheral edge thereof. In this case, however, there would be a concernthat the second supporting portion 142 would tilt such that its radiallyinner side is oriented toward the direction of the sealed fluid (L),which would cause the attitudes of the resin sealing member 120 andelastic sealing member 130 unstable.

Since the positioning precision of the fixing member 140 can beimproved, the attitude of the resin sealing member 120 can be madestable, so that the device can exhibit its sealing function in a stablemanner. Also, there is no need to dispose part of an elastic component(such as the outer peripheral sealing portion 731 of the elastic sealingmember 730 in the conventional example described above) on the outerside of the outer circumferential surface of the resin sealing member120, so that the sealing device 100 can be reduced in the radial size.

The annular space S2 is formed between an outer wall surface of theportion 144 connecting the cylindrical portion 141 and the secondsupporting portion 142 of the fixing member 140, and the elastic sealingmember 130. Therefore, the heat generated during the welding isprevented from being conducted to the elastic sealing member 130.

Furthermore, since the positioning precision of the fixing member 140can be improved as described above, the elastic sealing member 130 canbe positioned more precisely, so that the attitude of the elasticsealing member 130 is made stable. Also, the body portion 131 of theelastic sealing member 130 can make close contact with the innercircumferential surface of the case main body 111 more precisely.Accordingly, the sealing function on the outer circumferential side isfully achieved without the need to dispose part of an elastic component(such as the outer peripheral sealing portion 731 of the elastic sealingmember 730 in the conventional example described above) on the outerside of the outer circumferential surface of the resin sealing member120.

In addition, the fixing member 140 is fixed to the case main body 111 ina position where the repulsive force from the elastic sealing member 130applied on the second supporting portion 142 is within a predeterminedrange. Accordingly, the resin sealing member 120 and elastic sealingmember 130 can be fixed in position precisely.

Example 2

FIG. 4 shows Example 2 of the present disclosure. In the presentexample, a fixing member with a different structure from that of Example1 will be illustrated. Other features in the configuration and effectare the same as those of Example 1, and therefore the same constituentelements are given the same reference numerals and the descriptionsthereof are omitted.

The fixing member 140 according to Example 1 described above is providedwith the tapered portion 143 extending from the distal end of the secondsupporting portion 142 toward the direction of the sealed fluid (L) soas to increase in diameter. This tapered portion 143 is provided inorder to prevent the sealing lip portion 133 from separating from theouter circumferential surface of the shaft 200, as mentioned above.Depending on the environment of use, however, there may not be apossibility that the sealing lip portion 133 separates from the outercircumferential surface of the shaft 200. The metal fixing member 140 aaccording to the present example, therefore, is formed only by acylindrical portion 141 and a second supporting portion 142 extendingradially inward from an end portion of the cylindrical portion 141 on anopposite side (A) to the sealed fluid side (L). Thus the fixing member140 a according to the present example is not provided with the taperedportion 143 as in the fixing member 140 shown in Example 1.

Other features in the configuration of the fixing member 140 a are thesame as those of Example 1 described above, and therefore thedescriptions thereof are omitted. It goes without saying that the sameeffects as those of the sealing device 100 according to Example 1 areachieved by the sealing device 100 a according to the present example,too.

Example 3

FIG. 5 shows Example 3 of the present disclosure. While a configurationof the cartridge case made from one component was illustrated in thepreviously described Example 1, a configuration of the cartridge casemade from two components will be illustrated in the present example.Other features in the configuration and effect are the same as those ofExample 1, and therefore the same constituent elements are given thesame reference numerals and the descriptions thereof are omitted.

The cartridge case 110 a according to the present example is formed by afirst cartridge case 110A and a second cartridge case 1108 fixedlyattached to this first cartridge case 110A by press-fitting. The firstcartridge case 110A includes a cylindrical case main body 111, and anoutward flange 112 provided on the sealed fluid side (L) of the casemain body 111, these being in one piece. The second cartridge case 1108includes a first supporting portion 113 provided on the opposite side(A) to the sealed fluid side (L) of the case main body 111. Similarly toExample 1, the distal end portion of this first supporting portion 113is formed to incline toward the direction of the sealed fluid (L) so asto form a back-up portion 114 that supports the resin sealing member120. The roles and functions of the case main body 111, outward flange112, first supporting portion 113, and back-up portion 114 are as havebeen described in Example 1.

Configurations other than those of the cartridge case 110 a are the sameas those of Example 1 described above, and therefore the descriptionsthereof are omitted. It goes without saying that the same effects asthose of the sealing device 100 according to Example 1 are achieved bythe sealing device 100 b according to the present example. The fixingmember 140 a illustrated in the previously described Example 2 may beadopted in the sealing device 100 b according to the present example, aswell.

Example 4

FIG. 6 shows Example 4 of the present disclosure. While oneconfiguration in which the elastic member is an elastic sealing memberwas illustrated in the previously described Example 1, a configurationin which the elastic member does not have the sealing function will beillustrated in the present example. Other features in the configurationand effect are the same as those of Example 1, and therefore the sameconstituent elements are given the same reference numerals and thedescriptions thereof are omitted.

The elastic member 160 according to the present example is formed onlyby a cylindrical portion. Namely, it is formed only by a portioncorresponding to the body portion 131 of the elastic sealing member 130shown in the previously described Examples. Since the elastic member 160according to the present example does not include a sealing lip portion,it employs the fixing member 140 a illustrated in Example 2.

Configurations other than those of the elastic member 160 are the sameas those of Example 1 described above, and therefore the descriptionsthereof are omitted. It goes without saying that the same effects asthose of the sealing device 100 according to Example 1 are achieved bythe sealing device 100 c according to the present example, as well,except for the effects relating to the elastic sealing member 130.

(Others)

While a configuration was illustrated in various examples describedabove in which the first supporting portion 113 of the cartridge case110 or 110 a was provided with a back-up portion 114, the back-upportion 114 may not necessarily be provided depending on the environmentof use, such as when there is no need to support the resin sealingmember 120.

REFERENCE SIGNS LIST

-   10: Water pump-   21: Rotating shaft-   22: Bearing-   23: Pulley-   24: Impeller-   30: Housing-   100, 100 a, 100 b, 100 c: Sealing device-   110, 110 a: Cartridge case-   110A: First cartridge case-   110B: Second cartridge case-   111: Case main body-   112: Outward flange-   113: First supporting portion-   113 a: Protrusion-   114: Back-up portion-   120: Resin sealing member-   121: Body portion-   122: Sealing portion-   130: Elastic sealing member-   131: Body portion-   132: Cylindrical portion-   133: Sealing lip portion-   140, 140 a: Fixing member-   141: Cylindrical portion-   142: Supporting portion-   143: Tapered portion-   150: Outer peripheral sealing member-   160: Elastic member-   200: Shaft-   300: Housing-   500: Receiving jig-   510: Base portion-   520: Cylindrical portion-   600: Pressing member-   610: Pressing portion-   650: Laser light source-   L: Laser beam-   S1, S2: Annular space

The invention claimed is:
 1. A sealing device for sealing an annular gapbetween a shaft hole provided in a housing and a shaft inserted throughthe shaft hole, the sealing device comprising: a metal cartridge caseincluding a cylindrical case main body fitted to an innercircumferential surface of the shaft hole, and a first supportingportion extending radially inward from an end portion of the case mainbody on an opposite side to a sealed fluid side; a resin sealing memberprovided adjacent to the first supporting portion on the sealed fluidside and having a sealing portion that is slidable on an outercircumferential surface of the shaft; an elastic member providedadjacent to the resin sealing member on the sealed fluid side; and ametal fixing member including a cylindrical portion fixed to an innercircumferential surface of the case main body, a second supportingportion extending radially inward from an end portion of the cylindricalportion on the opposite side to the sealed fluid side, and a taperedportion extending from the distal end of the second supporting portiontoward the direction of the sealed fluid so as to increase in diameter,wherein an outer diameter of the cylindrical portion is set to be equalto or smaller than an inner diameter of the case main body, and thecylindrical portion and the case main body are being secured by welding,the resin sealing member and the elastic member are fixed by being heldin between the first supporting portion and the second supportingportion, the elastic member further includes an annular body portion anda cylindrical portion extending from a radially inner side of theannular body portion toward the direction of the sealed fluid, thefixing member further includes a bent portion bent in a curve thatconnects the second supporting portion and the tapered portion, the bentportion supporting an outer circumferential surface of the cylindricalportion of the elastic member, and a tip of the tapered portion isseparated from the outer circumferential surface of the cylindricalportion of the elastic member.
 2. The sealing device according to claim1, wherein an annular space is formed between an outer wall surface of aportion connecting the cylindrical portion and the second supportingportion of the fixing member, and the elastic member.
 3. The sealingdevice according to claim 1, wherein the annular body portion of theelastic member is provided between the resin sealing member and thesecond supporting portion and has an outer circumferential surface thatis in close contact with the inner circumferential surface of the casemain body; and the elastic member further includes a sealing lip portionprovided integrally with the body portion and being slidable on theouter circumferential surface of the shaft.
 4. The sealing deviceaccording to claim 1, wherein the fixing member is fixed to the casemain body at a position where a repulsive force from the elastic memberapplied on the second supporting portion is within a predeterminedrange.
 5. The sealing device according to claim 2, wherein the annularbody portion of the elastic member is provided between the resin sealingmember and the second supporting portion and has an outercircumferential surface that is in close contact with the innercircumferential surface of the case main body; and the elastic memberfurther includes a sealing lip portion provided integrally with the bodyportion and being slidable on the outer circumferential surface of theshaft.
 6. The sealing device according to claim 2, wherein the fixingmember is fixed to the case main body at a position where a repulsiveforce from the elastic member applied on the second supporting portionis within a predetermined range.
 7. The sealing device according toclaim 3, wherein the fixing member is fixed to the case main body at aposition where a repulsive force from the elastic member applied on thesecond supporting portion is within a predetermined range.